Motor



A. H, SKAER MoTon Filed FeB. 24, 1920 HIGH PRESSURE ggg. 1.

Patented May 26, 1925.

UNITED STATES Parleur caricia.

ARTHUR I-I. ISKAEJR, OF DENVER, O'LORADO, ASSIGNOR TOA THE DENVER ROCK DRILL MANUFACTURING COMPANYOF DENVER, COLORADO, A CORPORATION OF DELA- WARE.

Moron.

Application filed February 24, 1920.

The present invention relates to motors operated by an expansive motive fluid, preterably air. One of the primary objects is to provide an improved structure that has certain structural advantages, as will hereinafter appear, and is provided with means that will permit the necessary adpistment of the parts in order to insure the nonbinding action of the piston, while maintaining the necessary snug tit thereof.

A ui'ther and impoitant object is to provide a structure in which a high degree of etliciency can be obtained under different l[iuid pressures.

In the accompanying drawings Figure 1 is a longitudinal sectional view through the preferred embodiment of the invention,

Figure 2 is a cross sectional view on an enlarged scale. l

Figures 3 yand 4 are longitudinal sectional views through diiierent forms of theV interchangeable bushings that may be employed.

Similar reference numerals designate corresponding parts Vin all the ligui'es of the drawings.

In the embodiment disclosed, a cylinder member is provided comprising a barrel 5 having a detachable head 6. The barrel isv provided with a piston chamber 7, and the head 6 has a chamber 8 aligned with the chamber 7. A bushing 9 is located within the cylinder member and bridges the joint between the barrel 5 and head G, being pro-V vided with an eaternal flange 10 that is clamped between the two members. The bushing extends into the chamber 7 and also into the chamber 8, its rear end being tapered as shown at 11, so that said rear end is substantially tree ot the walls of the chamber 8. In the illustration, it may be explained that this taper has been greatly exaggerated in Serial No. 360,696.

order that it may show. As a matter ot tact, it is relatively slight. The bore 13 of the bushing constitutes'a reduced extension of the piston chamber 7.

The piston employed consists of a head 14 operating in the chamber 7, and provided with oppositely. disposedV extensions 15 and 16, said extensions corresponding in size and shape, so that the piston is reversible and either end may be used as the hammer head. The rear extension 15 operates inthe bore 13 of the bushing, while thefront extension is adapted to strike against the rear end ot a drill steel, as 17 placed in the chuck, designated generally by the reference numeral 18. Motive fluid from any suitable source is delivered to a longitudinal passageway 19 formed partly in the head 6 and partly in the barrel 5. The front end of the passage- 'way 19 terminates in a port 20 in the front` end of the cylinder member, and an annular groove 21 formed on Ithe extension 16 is adapted to move into and out ot communica tion with the port so as to permit thev motive iiuid to passinto the front endet1 the piston chamber 7 in advance of the piston head 14, as illustrated in Figure 1. The passageway 19 also has a lateral port 22 in communication with an annular groove 23 foi-ined in the periphery of the bushing 9, and this annular groove 23 has communica tion through a plurality of radial ports 24y with an internal groove 25 iii the walls of the bore 13 of said bushing. The rear eX- tension 15 of the piston has an annular groove 26 that is adapted to move into and out of register with the groove 25 and affords comn'iunication between said groove and the piston 7 in rear ot the head 14. An exhaust passageway 27 is in communication with the central portion of the piston chamber 7, and is adapted to be crossed by the head 14. In order to supply motive fluid to the rear end ot the rear extension 15, a plurality ot longitudinal ports 28 are formed through the walls of the bushing 9, and vconstitute a means oi communication between the rear end of the piston chamber 7 and the rear portion of the piston chamber 8. The rear end of the bushing 9 is spaced from the adjacent Wall of the head in order to allow for the said communication. A small port 29 affords constant communication between the channel 23 and the rear end of the piston chamber. This passage insures at all times the initial operation of the piston, irrespective of its position when the motive fluid is `admitted to the machine.

The operation of the structure is substantially as follows. lWhen air or other motive fluid is admitted to the passageway 19, assuming the piston in the position shown in Figure l, this motive fluid will pass from the port 20 through the channel 2l to the front end of the piston 7, and operating against the front face of the piston head 14g, will drive the piston rearwardly. The exhaust behind the piston is open through the port 27, as shown. As the piston approaches the rearward end of its stroke, the channel Y2G will come into communication'with the groove 25, While the port 2O will be cut ofil by the enlarged terminal portion of the extension 16. lVhen this takes place the piston head le has crossed the exhaust port 27, so that the chamber 7 in -advance of the head is opened to said ex-y haust. The motive fluid noiv passes through the ports 22 channel 23, ports 24, groove 25 and ,channel v26 into the piston chamber 7 8. The pistonk will consequently be drivenforwardly `and its entire area will be acted upon by the motive fluid. The employment of abushing 9 separate from the other parts is imp ortant from a structural standpoint, inasmuch Aas it permits the formation of the various ports and passages ivi-th ease and economy. It has beenv found `also that by having the bushing a sepa-rate vpart and allowing a slightfspaee between its rear end and the head Wall, as shown, it Will adjust itself to the piston, avoiding any binding action due to the cooking of :the piston. Another very material advantage is that it permits the use of interchangeable bushings With the ports 24 at different distances from the rear endof the piston chamber. Experience has demonstrated that Where the ports are at a 4fixed dista-nce, while they Will prove efficacious for one pressure, if employed for a different pressure there is a loss of effectiveness. Thus in the embodiment illustrated, if the set -ofports 2a are placed one-half inch from the front end of ythe bushing, as shown in Figure 3, the arrangement is highly satisfactory for a low pressure of say sixty pounds. 0n the other hand, if high pressure of approximately one hundred and ten pounds is utilized, then the ports 2li should. be placed farther from the front end of the bushing, as for example fifteen-sixteenths of an inch, as illustrated in Figure 4. This may be explained by the difference in the action of the air under different pressures. There the air pressure is low, it requires more time to act upon the piston than Where the pressure is high. As a consequence with the low pressure and the ports near the front end of the bushing, it will be obvious that the channel 26 will come into communication with. the channelv 25 sooner, andthe pressure of the live air will have a greater length of time to build up behind the piston head and rear extension. Furthermore rWhen the piston is returning the momentum or returning energy of the hammer is such that it is carried Well back toward the. face of thekbushing against this low pressure, permitting practically the maximum travel of the hammer. lith high pressure, hoeve ever, the action is much quicker, and if high pressure were used through ports close to the end of thel bushing the hammer would be stopped sooner and consequently' would not obtain its full stroke. lith 4the structure therefore, it Will be obvious that instead of a `different machine for different pressures, it only requires t-he change of the bushings.

From the foregoing, itis thought that the construction, operation and many advantages of the herein described invention will be apparent to those skilled i-n the art, Without further description, and it will be understood that various changesin the size, shape, proportion and minor details of construction, may be resorted to Without dcparting from the spirit or sacrificing vany of the advantages of the invention.

Having thus fully described my invcntion, what I claim as new, .and desire to secure by Letters Patent, is

l. A motor comprising a cylinder member having a piston chamber, and a bushing lixedly and removably located in the cylinder member and having a reduced bore in communication with the piston chamber, said boreforming an extension chamber, a pist-on having an active pressure surface in the piston chamber, and a reduced extension operating in the bushing and having a similarly Vfacing pressure surface, and means for distributing motive fluid lto the piston chamber outside the ,bushing to operate against the pressure surface of the piston in said chamber and ports lfor simultaneously delivering a portion .of said motive fluid from the piston chamber to the outer lend of the bushing bore and against the said pressure surface of thepist-on extension in said bore.

2. A motor comprising a cylinder member lia-ving a piston chamber and a bushing iixedly and removably located in the cylinder member and having a' bore in communication With the piston chamber and forming an extension chamber, alpiston in the piston chamber having a reduced extension operating in thepbushing, and means for supplying motive fluid through the bushing to the bore thereof and 'thence to the pistou chamber in advance of the bushing, said piston extension having means for controlling the said passage cf the motive fluid from the bore to the piston chamber, and said bushing having ports for permitting the return passage of such fluid from the piston chamber to vthe outer end of the bushing bore and against the piston extension.

3. A motor comprising a cylinder member having a barrel and a removable head, provided with alined chambers, a bushing in the chambers and clamped between the barrel and the head, a piston operating in the barrel chamber and having a reduced extension in the bushing, said bushing having transverse fluid supply ports, said piston having means for affording communication between the ports and the barrel chamber, and said bushing having longitudinal passageways independent of the sai-d communication adorded by the piston for directing motive fluid delivered into the barrel chamber therefrom into the head chamber.

4. A motor comprising a cylinder member having a piston chamber and an extension chamber communicating with the piston chamber, a piston in the chamber having an extension in the extension chamber, means controlled by the extension for supplying motive fluid to the piston chamber, and means in communication with the piston chamber for maintaining a constant supply oil" fiuid thereto.

5. A motor comprising a cylinder member having a piston chamber and a bushing in the member having a bore forming an eXtension chamber, and apiston in the chamber having an extension in the extension chamber, said bushing having a fluid supply port controlled by the piston for admitting` fiuid to Athe chamber, and said bushing having an initial fluid supply port in constant communication with said chamber.

6. In a motor, the combination with a cylinder having a piston chamber, of a piston operating in the chamber and having a surface against which the motive fluid acts to move said piston, and means for supplying motive fluid to the chamber to operate against said surface including devices adapted to vary the distance between the point of inlet of such motive fluid and the said face when the piston is at one limit of its stroke.

In a. motor, the combination with a cylinder member, of a piston operating therein and having an extension, and interchangeable bushings adapted to be placed in the cylinder and having ports that are respectively at different distances from the inner ends ofthe same, said extension being adapted to operate in the bushing placed'in the cylinder and controlling' the supply of fluid.

delivered through theports thereof.

8. In a motor, the combination with a cylindcr member, of a piston operating therein and having an extension .provided with a groove, and interchangeable bushings adapted to be placed in the cylinder and respectively having ports that are at differ-ent distances from the inner ends of the same, said extension operating in the bushing placed in the cylinder and the groove thereof moving into and out of connection with the ports of such bushing.

9. In a motor, the combination with a cylinder member, of a bushing therein having an annular groove in its periphery and a plurality of longitudinally disposed open ended passageways, means for supplying,

motive fluid to the groove, said bushing havtransverse ports between the longitudinal passageways and opening into the groove, and a piston operating in the cylinder member and having a reduced extension that operates in the bushing and is provided with a groove that communicates with the transverse ports.

l0. In a motor, the combination with a cylinder member, having` a motive fluid supply port, of a piston that operates in the cylinder member and having a reduced extension, a bushing adapted to be detachably mounted in the cylinder member and surround the piston extension, said bushing being provided With a port therethrough and being so constructed that said port may be located at different distances from the end of th-e bushing and still communica-te with the supply port of the cylinder member, and means carried by the piston extension for controlling the passage of motive fluid from the bushing port to the cylinder member in advance of the bushing.

1l. In a motor, the combination with a cylinder member having a motive fluid supply port, of a piston that operates in the cylinder member and having a reduced extension, a bushing member adapted to be detachably mounted in the cylinder member and surround the piston extensiomone of said members having a groove that communicates With the supply port and said bushing member having a transverse port of less extent than the groove, and means carried by the piston extension for controlling the passage of motive fluid from the bushing port to the cylinder member in advance of the bushing.

12. In a motor, the combination with a cylinder member having a motive fluid supply port, of a bushing therein having an external annular groove between its ends that isv in constant communication with the supply port, said bushing also having transverse inlet ports 'therethrough -tllat me in @0ngIteSSo-the motiyeuid Ainto thebusllfing. stent Communication with .t-lae groove Vand lntesi-mony whereof, I affix my signuzue of less diameter than ythe Width ther-eef, ture v1n the presence of two witnesses.

and n piston operating Vfn the cylinder mem# ARTHUR H. SKAER. ber and provided with ,a piston .extension lVltn'QSSGSI that operates in ythe bushing ,and .controls ,the SULLIVAN Y. THERo-N,

ports :therein to intermittently prevent al- F. SCHWARTZ.. 

